# std::basic_string<CharT,Traits,Allocator>::clear

From cppreference.com
< cpp‎ | string‎ | basic string

void clear(); |  | (noexcept since C++11) (constexpr since C++20)

Removes all characters from the string as if by executing erase(begin(), end()).

All pointers, references, and iterators are invalidated.

### Parameters

(none)

### Return value

(none)

### Notes

Unlike for std::vector::clear, the C++ standard does not explicitly require that capacity is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also shrink_to_fit).

### Complexity

Linear in the size of the string, although existing implementations operate in constant time.

### Example

Run this code

    #include <cassert>
    #include <iostream>
    #include <string>

    int main()
    {
        std::string s{"Exemplar"};
        std::string::size_type const capacity = s.capacity();

        s.clear();
        assert(s.empty());
        assert(s.size() == 0);
        std::cout << std::boolalpha << (s.capacity() == capacity) << '\n';
    }

Possible output:

    true

### See also

erase | removes characters (public member function)

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